Pilot training in the world's first robot-based flight simulator - developed by DLR in cooperation with Grenzebach Maschinenbau and KUKA.

Credit:
Grenzebach/DLR.

From the outside it looks like just a large industrial robotic arm with a cockpit, but to the pilot inside the simulator, it feels like a real aircraft. The pilot sits at the controls, and the flight commands are converted into corresponding movements of the robotic arm in real time. This is the first robot-based flight simulator in the world, and it will be used for training pilots. For its development, two researchers from the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) and their partners Grenzebach Maschinenbau and KUKA have been awarded the euRobotics Technology Transfer Award. The prize is awarded annually to projects that combine research findings with commercial applications. To achieve this, the two DLR engineers have, among other things, exposed dummies to numerous acceleration tests, designed the structure of the system and worked on tricky flight path planning – all to create the perfect illusion of flying.

Pilots are usually taught and trained on hexapod systems before undertaking real training flights. Here, student pilots sit in a cockpit that is mounted on a six-axis movable platform. The disadvantage of these systems is their price, ranging between seven and 25 million euros, making them too expensive for smaller flying schools. "A simulator mounted on an industrial robot would take these costs down to about one million euros," explains DLR researcher Tobias Bellmann, who received the award along with DLR engineer Johann Heindl and Olaf Gühring from Grenzebach Maschinenbau.

From car to helicopter

The researchers at the DLR Robotics and Mechatronics Center have been working on a simulator based on industrial robots since 2004. In 2010 they succeeded in interactively implementing flight on the robotic arm. The passengers no longer flew on predefined flight paths – they could control the capsule themselves. "For us, this means that the movements of the robotic arm have to be computed in real time – in other words really quickly – because they cannot be planned in advance," explains Bellmann. In 2011 the robotic arm received a new 'cockpit', inside which instruments could be swapped over as necessary: an aircraft control yoke, a steering wheel for a car, or helicopter flight controls. By refitting the cabin, the simulator was at times converted into the interior of a car, an aircraft or a helicopter – although the robotic arm and dome always stood in the test hall at the DLR facility in Oberpfaffenhofen.

DLR simulator

The research results have now been incorporated into the design of the Grenzebach DA42 pilot training simulator. "In this simulator, pilots can, for example, be trained for critical situations over and over again," says Bellmann. "In a training aircraft, this would not only be expensive but also dangerous." From the simulated cockpit of the Diamond DA42 aircraft, the pilot’s view always remains completely faithful to the one he would have on a real flight – regardless of the movements of the robotic arm. Experienced pilots from various airlines and aircraft companies have put the simulator to the test on numerous occasions. "This feedback was very important for us, so that we could make the simulation as realistic as possible," continues Bellmann. In the near future, aviation authorities are expected to certify the Grenzebach DA42 simulator as a Level D flight simulator – the highest category of qualification.

This means that pilots in the robot-based simulator will be able to experience situations that will save them in real life. "Our simulator enables extreme rolling and pitching movements, because there is plenty of room for the movements of the robotic arm," explains Bellmann. For pilots, this means that even inverted flight is effortlessly possible.

2 Comments

Interesting design and "sexy" look, but also very similar to several other R&D simulators that have been in development over the past few years. While this might currently have some excellent, but highly limited application, there are numerous obstacles to this design receiving a NAA Level D qualification. The training industry will watch all designs with interest.

It is worth correcting that the stated price of this device versus traditional flight simulators is misleading. To represent an aircraft to a Level D standard requires three areas of cost mostly outside the simulator manufacturer's control: 1) Aircraft and System Data IP license, 2) Aircraft Parts, and 3) Avionics. Each of these can cost upwards of 1M Euros each (very typically in the 3-5M Euro range), and comprise the majority of cost of a Level D simulator. There are reconfigurable simulators being produced, but that cost will essentially be repeated to some level for each aircraft represented. Simulator manufacturer's can get around some of these costs if they are willing to invest significant resources to develop their own IP, but they will have to recover those costs through their own IP license. All major aviation simulator manufacturers provide flight trainers that meet lower standards of qualification, with costs similar to or less than this trainer.

Also, no engineer could consider this design to be more a "robot" than the traditional, computer-driven, intelligently-controlled, hydraulic or electrically actuated motion systems; it just has a different look.

11/04/2013 12:11 -
from Tobias Bellmann

Dear Senator,

In response to your comment:

It is true, that IP licenses, aircraft parts and avionics are vast parts of the simulator price, but adding the cost of a classical hexapod to the DA42 Simulator would more than double the price of 1M Euro for this simulator. The commercial success of this simulator (more than 25 orders after half a year) speaks for the necessity for a full-motion simulator at this price level. As this simulator system targets light-weight training aircrafts, where no full motion simulators are available right now, the involved aircraft manufacturer companies support this system as it offers a missing link between the standard, fixed-based simulator for operational training and the main product, the training aircraft.

It is also true, that a hexapod is a robotic mechanics, the term robot in this article refers to serial, industrial robot arm systems, which are mass-produced for the manufacturing industry. These systems are by far cheaper compared to hexapods, which have a significant smaller market. The lower rotation point of hexapod simulators can also lead to unwanted sway movements while tilting the simulator cell. Using an industrial robot arm, the roll axis of the simulator can be placed in the same position as the roll axis of the airplane.

The reconfigurable DLR Robotic Motion Simulator is for research purposes only, in this environment, new cockpit designs, different human machine interfaces, path-planning algorithms etc. are tested, and therefore no qualification level is aspired for this simulator. The DA42 Simulator on the other hand features the complete avionics, instruments, force-feedback controllers of an actual DA42 Aircraft and is in qualification process right now.